Cutter heads for gear manufacture are generally disc-shaped and rotatable about a cutter head axis. A cutter head comprises a first side and a second side, one or more cutting blade positioning slots arranged in the cutter head with each of the blade positioning slots extending between the first and second sides. One or more stick-type (i.e. bar-type) cutting blades are positioned and clamped, usually via one or more clamp screws and clamp blocks, in each of the blade positioning slots.
Radial blade adjustment in stick blade cutter heads requires at least one adjustment screw adjacent to a main clamp screw. Inward movement of the adjustment screw causes a cutting blade to slide or roll in the cutter head whereby the radial location of the tip and cutting edge of the cutting blade is repositioned. Such radial repositioning assures the same radial position of all cutting edges (outside blades and/or inside blades) within a certain tolerance. For example, see WO 2014/074495 or WO 2014/093411.
Adjustment screws of radially adjustable cutters usually have fine treads, as opposed to the standard threads of a clamp screw, in order support the precise radial adjustment of the cutting blades. The torque on adjustment screws may vary between 2 and 20 Nm. In cases of low torque on the adjustment screws, it has been experienced that during the cutting process, especially after cutting a high quantity of parts, the adjustment screw may turn itself out which is believed to be caused by cutter vibration. Movement of an adjustment screw will change the radial position of the respective cutting blade thereby positioning the cutting blade radially out-of-line with the remaining blades in a cutter head.
If an adjustment screw loosens during the cutting of a quantity of parts, the advantage of radial blade truing is diminished or even eliminated.